METHODOLOGY:We tested a combination of short-term weather forecasts from the Weather Research and Forecasting Model (WRF) to predict in season weather variables, such as, maximum and minimum temperature, precipitation, and radiation at four different forecast lengths (14days, 7days, 3days, and 0days). This forecasted weather data along with the current and historic (previous 35 years) data were combined to drive Agricultural Production Systems sIMulator (APSIM) in-season corn [Zea mays L] and soybean [Glycine max] grain yield and phenology forecasts for 16 field trials in Iowa, USA.

Figure 1. Visual representation of combining weather with the crop model to obtain yield and phenology predictions. Weather is broken down into 3 categories, current, WRF forecasts (3, 7, and 14 day), and 35 years of historical weather.